[HDFS-13027] Handle possible NPEs due to deleted blocks in race condition

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.2.0, 3.0.4, 3.1.2
• Component/s: namenode
• Hadoop Flags: Reviewed
• Assignee: Vinayakumar B
• Reporter: Vinayakumar B
• Created: 17/Jan/18 10:20
• Updated: 31/Aug/18 02:43
• Resolved: 30/Aug/18 16:51

Description

Since File deletions and Block removal from BlocksMap done in separate locks, there are possibilities of NPE due to calls of blockManager.getBlockCollection(block) returning null.

Handle all possibilities of NPEs due to this.

Issue Links

• is related to: HDFS-8330 BlockInfoContiguous in blocksMap can have null BlockCollection
• is related to: HDFS-12638 Delete copy-on-truncate block along with the original block, when deleting a file being truncated
• is related to: HDFS-12880 Disallow abandoned blocks in the BlocksMap